Content matching advertising, in which advertisements are displayed in accordance with content of Web pages, or keyword targeted advertising, in which advertisements are displayed in accordance with search keywords in search engines, are some examples of widely used ways of displaying advertisements on Web pages. Advertisement are created in a predetermined size and then displayed in display spaces on Web pages. Japanese Laid-open Patent Publication No. 2009-53219 discloses a technology that displays banner advertisements in a smaller space by dividing a display space into more than one areas and displaying reduced-size versions of advertisements in these areas.
In reality, the design of advertisements varies and the size of the advertisements can be freely determined by designers. However, the conventional technology, such as the system disclosed in Japanese Laid-open Patent Publication No. 2009-53219, is based on the assumption that advertisements are submitted in the same size, and thus is not able to handle advertisements in different sizes.